1. Technical Field
The present invention relates to electro-optic devices and electronic apparatuses. In particular, the present invention relates to an electro-optic device in which light-shielding properties against light leaking from a light source are high and a cutting step of a substrate having a black mask (which may also be referred to as a black matrix) can be performed readily, and also to an electronic apparatus equipped with such an electro-optic device.
2. Related Art
As an electro-optic device of related art, a liquid crystal device is widely used. Specifically, a liquid crystal device has a plurality of pixel areas defined by opposite areas of electrodes. Voltage applied to each pixel area is selectively turned on and off so as to modulate light passing through a liquid crystal material of the pixel area, whereby a picture image or character image can be displayed on the entire display region.
Although liquid crystal display devices of a double-sided display type have been proposed for multifunctional purposes, such double-sided-display-type liquid crystal display devices are problematic in that it is difficult to obtain sufficient brightness in comparison to single-sided-display-type liquid crystal display devices. This is because liquid crystal panels defining the opposite surfaces of a double-sided display type are illuminated with a single light source and light guide plate.
JP-A-2004-46050 (Claims and FIG. 1) discloses a liquid crystal display device of a double-sided display type as shown in FIG. 14. This liquid crystal display device has a single light guide plate 302 with a light source 301 disposed adjacent to one edge thereof. Moreover, liquid crystal display panels 307 and 308 are respectively disposed adjacent to the opposite surfaces of the light guide plate 302. The liquid crystal display panel 307 and the light guide plate 302 have a reflective polarizing plate 305 interposed therebetween, and likewise, the liquid crystal display panel 308 and the light guide plate 302 have a reflective polarizing plate 306 interposed therebetween. These reflective polarizing plates 305 and 306 have adjusted penetrating axes.
More specifically, the penetrating axis of the reflective polarizing plate 305 is aligned with the penetrating axis of a liquid-crystal-panel polarizing plate 309, which faces the reflective polarizing plate 305 and is disposed at the same side as the reflective polarizing plate 305 with respect to the light guide plate 302. Likewise, the penetrating axis of the reflective polarizing plate 306 is aligned with the penetrating axis of a liquid-crystal-panel polarizing plate 310, which faces the reflective polarizing plate 306 and is disposed at the same side as the reflective polarizing plate 306 with respect to the light guide plate 302. Moreover, the penetrating axes of the reflective polarizing plate 305 and the liquid-crystal-panel polarizing plate 309 are orthogonal to the penetrating axes of the reflective polarizing plate 306 and the liquid-crystal-panel polarizing plate 310 that are disposed opposite to the plates 305 and 309 across the light guide plate 302.
JP-A-2000-338504 (Claims and FIG. 1) discloses a color liquid-crystal display device that is equipped with a color filter and prevents light leakage from a peripheral frame region.
In detail, FIG. 15 shows a color liquid-crystal display device of a horizontal electric field type that has a color filter substrate 406a having a color layer 405a divided into segments in the display region by a black matrix 404a and also having a black matrix 404bextending in the shape of a picture frame along the periphery of the display region.
More specifically, this liquid-crystal display device includes the color filter substrate 406a having a first protective film 407a disposed over the color layer 405a and the black matrix 404b, and an electrode substrate 406b having a second protective film 407b disposed over electrodes 410a and 410b that drive switching elements TFT for pixel selection. Moreover, the color filter substrate 406a and the electrode substrate 406b have a liquid crystal layer 411 sealed therebetween with a sealant 412.
The black matrix 404a in the display region of the color filter substrate 406a has disposed thereon first-color-layer pillars 405b each of which is constituted by at least one color layer. On the other hand, the black matrix 404b in the peripheral frame region of the color filter substrate 406a has disposed thereon a second-color-layer pillar 405cconstituted by stacked films of the three primary colors and extending in the shape of a picture frame.
However, even with the double-sided-display-type liquid crystal device disclosed in JP-A-2004-46050, there are still problems in that the effective use of light from the light source is insufficient and that it is difficult to guide the light evenly.
More specifically, there are cases where the inner edges of a frame are provided with recesses and the outer edges of the light guide plate are provided with projections. These recesses and projections are used for the positioning of the light guide plate when optical members such as the light guide plate and the reflective plates are to be accommodated within the frame. The recesses and projections are engaged with each other so as to serve as positioning members for the light guide plate. Where these projections are provided in the light guide plate, the light guide plate extends close to the outer edges of the frame. Although a light-shielding tape is disposed around the display region, the light-shielding tape has dimensional tolerance or adhesive tolerance and cannot properly shield the aforementioned projections of the light guide plate. This leads to a light leakage from the periphery of the light-shielding tape.
In addition, double-sided-display-type liquid crystal display devices of recent years have been significantly reduced in thickness, and the thickness of the frame has been reduced accordingly. For this reason, the light from the light source unfavorably passes the frame and leaks to the outside.
On the other hand, the color filter substrate equipped with the black matrix disclosed in JP-A-2000-338504 is fabricated by cutting a substrate of a large surface area having a black matrix into pieces. This is problematic in that the production yield is low and that cutting chips are formed easily due to the black matrix.